This read-only integer reports the highest receive signal level, in dBm, recorded by the link interface during the current, still-open 15-minute interval. An engineer checks this to see the best signal the link has achieved so far within this short window, useful for judging how much the signal is fluctuating in real time. For example, a small gap between wvlinkCurrentMaximumRSL and wvlinkCurrentMinimumRSL would indicate a stable, non-fading signal during this interval.